The invention relates to a cantilevered composite structure plate for double floors, decks, roofs or the like, with a trough serving as outside reinforcement and made of a material with high tensile strength and high elasticity module, preferably sheet steel, and a filler material of low tensile strength and low elasticity module, e.g. anhydrite or concrete, placed in the hollow of the trough, and also with an armature in the trough floor, preferably in the form of funnel-shaped holes, and the invention also relates to a process for the manufacture of such composite structure plates.
A similar composite structure plate has been disclosed by the DE-PS No. 2004101. In this embodiment, the trough serving as outside reinforcement is generally of sheet steel in square shape, manufactured by deep-drawing, whereby the essentially smooth-surfaced trough floor overlaps on all four sides onto the perpendicular walls. It is also known to impress stiffening corrugations therein in cross arrangement, to stiffen the trough floor. Such deep-drawn troughs, however, are relatively expensive to manufacture and require deep-drawing as well as static ratios of the finished composite structure plates requiring rather thick-walled metal sheets for the troughs, which further increases the cost. The statically neutral plane in this known composite structure plate lies at only a relatively small distance over the trough floor in the filler material of low tensile strength and low elasticity module. This means that the leverage between the statically neutral plane or zone and the trough floor which is serving as outside reinforcement is very small relative to the thickness of the filler material, and thus requires a correspondingly thick trough floor. This is also one of the reasons why this plate construction cannot be used efficiently over a large span width or length. In addition, troughs cannot be efficiently manufactured with large and variable dimensions in the deep-drawing process.
Similarly, the ratios in the structural plate are disclosed by the DE-PS No. 1 609 740, in which the side walls of the trough are provided with an edge outside the weaker material found in the hollow space of the trough, which should prevent e.g. buckling of the side walls of the trough during filling of the weaker material. This patent specification also shows an embodiment in which the smooth trough of strong material is used as cover plate, with insertion of a weak layer in a corresponding superstructure trough of strong material. Thus, a particularly rigid plate is obtained which must bear heavy flex stresses, which however requires two deep-drawn troughs, and thus is still more expensive than the above composite structure plate. This construction is practically not at all suitable for large span widths or lengths.
A sheathing plate is also disclosed in DE-AS No. 21 50 959, serving as reinforcement for a concrete covered deck formed of sheet metal (hidden sheathing), which has parallel rods of different cross sections, anchored in the concrete layer, which give the sheathing plate a resistance and inertia moment sufficient for the installation. These constructions, however, cannot be simply switched over to cantilevered composite structure plates of the above type with outside trough-like reinforcement.